Good Riddance to Polio: A Conquered Disease Still Clings to Life

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Editor's note: This story is part of a series of online exclusives about natural phenomena and human endeavors we'd like to see come to an end. They are connected with the September 2010 special issue of Scientific American called "The End".

Poliomyelitis—a viral disease that wreaks havoc on motor neurons, often paralyzing sufferers for life—was supposed to be banished from the planet a long time ago. When Jonas Salk unveiled his famed vaccine to the world in 1955, and Albert Sabin introduced an oral version shortly thereafter, inoculations began in earnest in many parts of the world, drastically lowering incidence numbers. Polio was completely eradicated in North and South America by 1994; in Australia and China by 2000; and in Europe by 2002.

Even so, cultural animosities in isolated pockets of the world have conspired to keep global health authorities from stamping out the disease altogether. In 2003, for instance, the World Health Organization's Global Polio Eradication Initiative mounted a Herculean effort to vaccinate 15 million Nigerian children.

But prominent leaders from the country's Islamic community tarred and feathered the campaign, warning citizens that the vaccine was part of an imperialist U.S. plan to keep Nigeria's population down. "We believe that modern-day Hitlers have deliberately adulterated the oral polio vaccines with antifertility drugs and…viruses which are known to cause HIV and AIDS," prominent physician Datti Ahmed told journalists at the time. Part of the suspicion traces back to the late 1990s, when U.S.-based drug company Pfizer showed up to administer a test of its experimental drug Trovan in the wake of a meningitis epidemic. Dozens of Nigerian children suffered major side effects, including paralysis, deafness and liver damage.

After the failure of the Nigerian campaign the WHO overhauled its vaccination strategy. Previous campaigns had been run at a national level with a top-down structure, but WHO officials started taking a more piecemeal approach, getting to know prominent opinion-makers within smaller communities before beginning vaccination drives. "We overcame the problem by working with the local populations—traditional leaders and religious leaders," says WHO spokesperson Sona Bari. "There is a leadership structure that predates the modern nation-state, which the people trust much more."

Once traditional Nigerian leaders understood the pressing need for the vaccine and became convinced of the good will of the WHO workers, "they took ownership of the program," Bari says. After citizens heard trusted leaders speak about the vaccine and its potential to save lives they gladly began lining up for doses, and disease rates began to plummet.

The resulting improvement in Nigeria's polio situation has been dramatic. Although 300 cases of polio were reported in Nigeria last year, only a handful of cases have been recorded this year to date.

To build on its Nigerian success, the WHO kicked off a similarly structured vaccination drive in March targeting 85 million children in 19 western African countries. The organization has opted for politically savvy localized strategies in other areas where polio is still endemic, including India and Afghanistan. "Let's say there's a conflict in Kandahar and we know from our political analysis which strongmen are allied with the Taliban and who favors the government," Bari says. "We use locals to figure out how we are going to ensure safe passage for our vaccinators."

Still, the global fight against polio is far from over. About 1,000 cases occur each year worldwide, costing the global economy $700 million—and Bari knows just how quickly one or two isolated incidents can mushroom into dozens. And west African nations are not the only ones that are vulnerable; Bari notes that in April an outbreak occurred in Tajikistan. "We're so close in the endemic countries," she says, "but this disease is going to cause outbreaks until you eradicate it."